Safety, efficacy and glucose turnover of reduced prandial boluses during closed-loop therapy in adolescents with type 1 diabetes: a randomized clinical trial
Jackson, Nicola C
Umpleby, A Margot
Diabetes, Obesity and Metabolism
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Elleri, D., Biagioni, M., Allen, J., Kumareswaran, K., Leelarathna, L., Caldwell, K., Nodale, M., et al. (2015). Safety, efficacy and glucose turnover of reduced prandial boluses during closed-loop therapy in adolescents with type 1 diabetes: a randomized clinical trial. Diabetes, Obesity and Metabolism, 17 1173-1179. https://doi.org/10.1111/dom.12549
ABSTRACT Aims: We evaluate safety, efficacy and glucose turnover during closed-loop with meal announcement using reduced prandial insulin boluses in adolescents with type 1 diabetes(T1D). Materials and methods: Randomized cross-over study comparing closed-loop with standard prandial insulin boluses versus closed-loop with prandial boluses reduced by 25%. Eight adolescents with T1D [M3; age 15.9(1.5)yrs; A1C 8.9(1.6)%; mean(SD); total daily dose 0.9(0.7, 1.1)IU/kg/d; median(IQR)] studied on two 36-hour-long visits. In random order, subjects received closed-loop with either standard or reduced insulin boluses administered with main meals [(50-80g carbohydrates(CHO)] but not with snacks (15-30gCHO). Stable-label tracer dilution methodology measured total glucose appearance (Ra_total) and glucose disposal (Rd). Results: Time in target (70-180mg/dl) was comparable [74(66,84)% vs 80(65,96)%, p=0.87] and so was time above 180mg/dl [21.8(16.3,33.5)% vs 18.0(4.1,34.2)%, p=0.87] and below 70mg/dl [0(0,1.5)% vs 0(0,1.8)%, p=0.88]. Mean plasma glucose was identical during the two interventions [152(16) vs 152(17)mg/dl, reduced vs standard bolus, p=0.98]. Hypoglycemia occurred once 1.5h post-meal during closed-loop with standard bolus. Overall insulin delivery was lower with reduced prandial boluses [61.9(55.2,75.0) vs 72.5(63.6,80.3)IU, p=0.01] and resulted in lower mean plasma insulin concentration [186(171,260) vs 252(198,336)pmol/l, p=0.002]. Lower plasma insulin was also documented overnight [160(136,192) vs 191(133,252)pmol/l,p=0.01, pooled nights]. Ra_total was similar [26.3(21.9,28.0) vs 25.4(21.0,29.2)μmol/kg/min, p=0.19] as well as Rd [25.8(21.0,26.9) vs 25.2(21.2,28.8)μmol/kg/min, p=0.46]. Conclusions: Twenty five percent reduction of prandial boluses during closed-loop maintains comparable glucose control in adolescents with T1D whilst lowering overall plasma insulin levels. It remains unclear whether closed-loop therapy with 25% reduction of prandial boluses will prevent postprandial hypoglycemia.
Closed-loop insulin delivery, post-prandial hypoglycemia, type 1 diabetes
US National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK085621). Support for the Artificial Pancreas research programme by the JDRF, Diabetes UK, NIHR Cambridge Biomedical Research Centre, and Wellcome Trust Strategic Award (100574/Z/12/Z) is acknowledged.
Wellcome Trust (100574/Z/12/Z)
Cambridge University Hospitals NHS Foundation Trust (CUH) (Roman Hovorka)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (R01DK085621)
External DOI: https://doi.org/10.1111/dom.12549
This record's URL: https://www.repository.cam.ac.uk/handle/1810/249260
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Licence URL: http://creativecommons.org/licenses/by/4.0/